It is often said that the eye is like a camera. The reason that the eye can “zoom” in and out is that the contraction and relaxation of the ciliary muscle changes the degree of the lens, thus adjusting the focus so that the image can fall clearly on the retina. Most people, around the age of 40 to 45, experience a decrease in “zoom” ability due to aging of the lens and weakening of the ciliary muscle, which can be seen as increasing strain when looking at the near side, and when reading newspapers, they cannot read small letters clearly and need presbyopic glasses to see clearly. The following points should be noted about presbyopia: 1. Presbyopia is mainly caused by the deterioration of vision when looking at the near, looking at the far is generally not affected. Therefore, the elderly can not attribute all vision loss to presbyopia. If there is a significant decrease in vision at a distance, attention should be paid to the presence of cataracts, glaucoma and other diseases. 2, presbyopia glasses when with that, do not delay. Presbyopia is a normal physiological process, generally 45 years old when the presbyopia degree is +1.50D (i.e. 150 degrees) or so, age every 5 years, the presbyopic lens degree increased by about 50 degrees. Some people think they can’t take them off if they wear them, and they don’t want to be old and hold on to them, which is not scientific. If you don’t wear glasses when you look close to your presbyopia, it will inevitably cause an overload on your eyes and produce all kinds of fatigue, such as headaches, eye swelling, blurred vision, etc. 3, with presbyopic glasses also need to first optometry. Some elderly friends two eyes presbyopia degree is not the same, or originally there is farsightedness, myopia, astigmatism, etc., without the examination to buy a pair of presbyopic glasses to wear, not only can not solve the problem, but also cause diplopia, eye distension and many other discomforts. 4, presbyopia suddenly become better may be the signal of some eye disease. Some elderly people who have had presbyopia for many years have suddenly gotten better vision and do not need to wear presbyopic glasses when reading books and newspapers, which may be caused by changes in the refractive power of the lens caused by cataracts. In summary, the appearance of presbyopia and its gradual deepening is a physiological and pathological change of the visual organ, which is one of the natural manifestations of human aging. Older people should have a correct understanding of it and treat it in a scientific and correct way to do a good job of eye care and disease prevention.